Lactic acid bacteria with high yield of gamma-aminobutyric acid and application of lactic acid bacteria in fermentation of fruit juice foods such as Chinese wolfberry and like

Abstract

The invention discloses lactic acid bacteria with high yield of gamma-aminobutyric acid and application of the lactic acid bacteria in fermentation of fruit juice food such as medlar, and belongs to the technical field of food. The lactobacillus plantarum LP-GB 01-21 provided by the invention is used for fermenting fruit juice such as Chinese wolfberry, the fermentation method is simple to operate and short in fermentation time, the content of gamma-aminobutyric acid in the fermented fruit juice is increased, the flavor and health-care efficacy of the fruit juice such as the Chinese wolfberry are reserved to the greatest extent, agricultural resources are fully utilized, the varieties of the fermented fruit juice are enriched, the environment is protected, and the lactobacillus plantarum LP-GB 01-21 is suitable for industrial production. The economic benefit and the social benefit are improved.

Description

Technical Field

[0001] The present invention relates to a lactic acid bacterium with high γ-aminobutyric acid productivity and its application in fermenting fruit juice foods such as wolfberry, belonging to the field of food technology. Background Art

[0002] Lactic acid bacteria are an important class of probiotics, widely used in multiple fields such as the food industry, medicine, and feed. They can produce lactic acid by fermenting sugars. The application of lactic acid bacteria in the food industry has a history of thousands of years. Lactic acid bacteria fermentation can not only effectively extend the shelf life of food, but also improve the nutritional function of food and endow food with a unique fermented flavor. Currently, there are many types of lactic acid bacteria applied in the food industry, mainly including Lactobacillus acidophilus, Lactobacillus bulgaricus, Streptococcus lactis, Bifidobacterium, Lactobacillus plantarum, etc. There are also many types of lactic acid bacteria fermentation products, mainly including fermented dairy products, fermented meat products, fermented fruit juice products, fermented bean products, and fermented cereal products, etc., bringing diverse choices and health benefits to our food culture.

[0003] γ-Aminobutyric acid (GABA) is a four-carbon non-protein amino acid and an inhibitory neurotransmitter, which has a significant regulatory effect on the nervous system. Through inhibitory nerve conduction, GABA provides great advantages for the treatment of human mental diseases. It can protect overexcited neurons, enhance brain vitality, and has multiple effects such as sedation and detoxification. In addition, GABA also has various physiological functions, such as calming the nerves, lowering blood pressure and diuresis, and has extremely small side effects. It is a very valuable functional ingredient. At present, a variety of lactic acid bacteria capable of synthesizing GABA have been reported, including Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus paracasei, Lactococcus lactis and Enterococcus avium, etc. However, the reported GABA synthesis ability of lactic acid bacteria is generally low (generally less than 50 g / L), which limits the practical application. Therefore, it is particularly important to provide a Lactobacillus plantarum with high γ-aminobutyric acid production in the current food fermentation field. Antioxidant property is an important characteristic of functional foods. Antioxidants can inhibit oxidation reactions in foods, reduce the degree of oxidation of unsaturated fatty acids, prevent food spoilage, discoloration and the generation of peculiar smells, thereby effectively extending the shelf life of fermented foods; they can also enhance the bioavailability of nutrients, improve the flavor and color of foods, and improve food quality; in addition, antioxidant substances in fermented foods can help the human body scavenge free radicals, reduce the damage of oxidative stress to cells, and thus prevent and delay the occurrence of various chronic diseases. Therefore, the preparation of fermented foods with high antioxidant properties has broad market application prospects. And the preparation of functional foods that can both produce high yields of γ-aminobutyric acid and have antioxidant properties will help improve the value of fermented foods and promote industrial production. Fermented fruit juice is a product obtained by fermenting fruits or fruit juices as substrates. In the prior art, strains that can produce high yields of γ-aminobutyric acid in a culture medium environment have been reported. However, due to the unique properties of fruit juices, whether these strains can grow normally in the fruit juice fermentation substrate, produce high yields of γ-aminobutyric acid, and improve the antioxidant property of the fruit juice and produce other beneficial substances cannot be expected.

[0004] In the prior art, there has been no report on functional fermented fruit juice products that have both high levels of γ-aminobutyric acid, antioxidant properties and a variety of active substances. Summary of the Invention

[0005] To solve the above technical problems, the present invention screened a lactic acid bacterium with high γ-aminobutyric acid production from the strains preserved in the laboratory and applied it to the fermentation production of fruit juice foods such as wolfberry. This strain can grow and reproduce normally in the culture medium and produce high yields of γ-aminobutyric acid. However, it is difficult to predict whether the strain can retain the function of producing high yields of γ-aminobutyric acid in fermented fruit juice, and it is also difficult to predict whether the strain can produce new characteristics in fermented fruit juice.

[0006] Technical Solution:

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The first object of the present invention is to provide the application of the Lactobacillus plantarum LP-GB 01-21 with high γ-aminobutyric acid production, specifically to prepare a juice fermented food rich in γ-aminobutyric acid, polyphenols and flavonoids by using the Lactobacillus plantarum LP-GB 01-21 with high γ-aminobutyric acid production.

[0009] The second object of the present invention is to provide a method for preparing a juice fermented food rich in γ-aminobutyric acid, lactic acid, polyphenols and flavonoids, and the method is to use the Lactobacillus plantarum LP-GB 01-21 with high γ-aminobutyric acid production.

[0010] Furthermore, the method is to add Lactobacillus plantarum LP-GB 01-21 for fermentation in the fermentation stage.

[0011] Furthermore, the production process of the preparation method specifically includes the following steps:

[0012] S1. Adjust the original juice pulp to a sugar degree of 12 - 14 °Brix;

[0013] S2. Activate the strain of Lactobacillus plantarum LP-GB 01-21 to obtain a Lactobacillus plantarum seed solution;

[0014] S3. Inoculate Lactobacillus plantarum LP-GB 01-21 into juices such as wolfberry juice, and ferment at 35 °C - 37 °C for 8 - 12 h to obtain a juice fermentation broth;

[0015] S4. Filter and sterilize the juice fermentation broth to obtain the fermented juice.

[0016] Furthermore, according to the method, in step S3, the inoculation amount of the Lactobacillus plantarum LP-GB 01-21 seed solution is 1% - 5% (v / v), and the biomass of the Lactobacillus plantarum LP-GB 01-21 seed solution is 1×10 6 CFU / mL or OD600 0.8 - 1.2.

[0017] Furthermore, according to the method, in step S3, during fermentation, static fermentation is carried out.

[0018] Furthermore, in step S3, the end point of fermentation is that the biomass of Lactobacillus plantarum is above 8.50 lg CFU / mL - 9.5 lg CFU / mL, and the total acid calculated as lactic acid can reach above 2.03 g / 100 mL.

[0019] Furthermore, in step S1, the original juice pulp includes wolfberry original pulp, apple concentrated juice or mulberry concentrated juice.

[0020] Further, in step S2, the method for preparing the seed liquid is as follows: Lactobacillus plantarum LP-GB 01-21 is cultured in MRS medium at 35°C - 37°C for at least 18 h.

[0021] Further, in step S4, the sterilization is pasteurization.

[0022] The present invention also provides a fermented fruit juice prepared by the above method.

[0023] The third object of the present invention is to provide the use of Lactobacillus plantarum LP-GB 01-21 in the preparation of a fermented fruit juice rich in GABA, lactic acid, polyphenols and flavonoids.

[0024] The fourth object of the present invention is to provide the use of Lactobacillus plantarum LP-GB 01-21 in improving the antioxidant property of fruit juice.

[0025] The fifth object of the present invention is to provide the use of Lactobacillus plantarum LP-GB 01-21 in the preparation of fermented foods.

[0026] Beneficial effects:

[0027] The Lactobacillus plantarum LP-GB 01-21 provided by the present invention is used for fermenting fruit juices such as wolfberry juice. The fermentation method is simple to operate and has a short fermentation time. It increases the content of γ-aminobutyric acid in the fermented fruit juice, maximally retains the flavor and health care effects of fruit juices such as wolfberry juice, makes full use of agricultural resources, enriches the variety of fermented fruit juices, protects the environment, and improves economic and social benefits. Specific embodiments

[0028] According to the following embodiments, the present invention can be better understood. However, those skilled in the art can easily understand that the specific material ratios, process conditions and their results described in the embodiments are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0029] The Lactobacillus plantarum LP-GB 01-21 involved in the following embodiments has been disclosed in Patent CN101928679A.

[0030] Example 1: Fermentation of wolfberry puree

[0031] (1) Adjust the sugar degree of wolfberry puree

[0032] Water and wolfberry puree are blended to adjust the sugar degree of wolfberry puree to 12 - 14 °Brix and measured with a saccharimeter.

[0033] (2) Activation culture

[0034] Activation of Lactobacillus plantarum LP-GB 01-21: Using an inoculation loop, pick a small amount of colonies from the original strain slant (or ampoule) under aseptic conditions, place them on an MRS plate medium for streaking, and then incubate at 37°C for 24 h. Incubate statically. After inspection, there are no contaminants, the bacterial cells grow neatly. Macroscopically observed, the colonies are plump. After smear and staining inspection, there are no contaminants. Pick a single colony and place it in an MRS liquid medium. Control the liquid volume of the liquid medium to be 20% of the Erlenmeyer flask, and then incubate at 37°C statically for 18 h.

[0035] (3) Fermentation culture

[0036] Fermentation stage: Pump the original wolfberry pulp into the fermenter. Inoculate the well-activated Lactobacillus plantarum LP-GB 01-21 into the fermenter at an inoculation amount of 1%-5% (v / v). The biomass OD600 of the well-activated Lactobacillus plantarum LP-GB 01-21 seed liquid is 0.8-1.2. Keep the temperature at 37°C. The fermentation stage lasts for 8-12 h. At the end of fermentation, the viable count can reach above 8.50 lgCFU / mL, and the total acid calculated as lactic acid can reach above 2.03 g / 100 mL.

[0037] (4) Treatment of the original wolfberry pulp after fermentation

[0038] Centrifuge and filter the fermentation broth, sterilize it at 62°C - 65°C for 30 minutes using the pasteurization method, and then package it to obtain the fermented wolfberry original pulp rich in γ-aminobutyric acid.

[0039] Example 2: Fermented apple juice

[0040] (1) Adjust the sugar content of apple concentrate

[0041] Blend water and apple concentrate, adjust the sugar content of the apple concentrate to 12 - 14 °Brix, and measure it with a saccharimeter.

[0042] (2) Activation culture

[0043] Activation of Lactobacillus plantarum LP-GB 01-21: Using an inoculation loop, pick a small amount of colonies from the original strain slant (or ampoule) under aseptic conditions, place them on a plate medium for streaking, and then incubate at 37°C for 24 h. Incubate statically. After inspection, there are no contaminants, the bacterial cells grow neatly. Macroscopically observed, the colonies are plump. After smear and staining inspection, there are no contaminants. Pick a single colony and place it in a liquid medium. Control the liquid volume of the liquid medium to be 20% of the Erlenmeyer flask, and then incubate at 37°C statically for 18 h.

[0044] (3) Fermentation culture

[0045] Fermentation stage: The apple juice with adjusted sugar content is pumped into the fermentation tank. The activated Lactobacillus plantarum LP-GB01-21 is inoculated into the fermentation tank at an inoculation amount of 1%-5%. The temperature is maintained at 37°C. The fermentation stage lasts for 8-12 hours. The viable count can reach above 8.30 lg CFU / mL, and the total acid calculated as lactic acid can reach above 2.21 g / 100 mL.

[0046] (4) Treatment of fermented apple juice

[0047] The fermented liquid is centrifuged, filtered, sterilized, and packaged to obtain fermented apple juice rich in γ-aminobutyric acid.

[0048] Example 3: Fermented mulberry juice

[0049] (1) Adjust the sugar content of mulberry concentrated juice

[0050] Water and mulberry concentrated juice are blended, and the sugar content of the mulberry concentrated juice is adjusted to 12-14 °Brix and measured with a saccharimeter.

[0051] (2) Activation and cultivation

[0052] Activation of Lactobacillus plantarum LP-GB 01-21: With an inoculation loop, pick a small amount of colonies from the original strain slant (or ampoule) under sterile conditions, streak on the plate medium, then incubate at 37°C for 24 hours, statically cultivate. After inspection, there are no contaminants, the bacterial cells grow neatly, macroscopically observed, the colonies are plump, smear and stain inspection shows no contaminants. Pick a single colony and place it in the liquid medium, control the liquid volume of the liquid medium to be 20% of the Erlenmeyer flask, then incubate at 37°C statically for 18 hours.

[0053] (3) Fermentation and cultivation

[0054] Fermentation stage: The mulberry juice with adjusted sugar content is pumped into the fermentation tank. The activated Lactobacillus plantarum LP-GB01-21 is inoculated into the fermentation tank at an inoculation amount of 1%-5%. The temperature is maintained at 37°C. The fermentation stage lasts for 8-12 hours. The viable count can reach above 8.42 lg CFU / mL, and the total acid calculated as lactic acid can reach above 2.42 g / 100 mL.

[0055] (4) Treatment of fermented mulberry juice

[0056] The fermented liquid is centrifuged, filtered, sterilized, and packaged to obtain fermented mulberry juice rich in γ-aminobutyric acid.

[0057] Control Example 1

[0058] The types of raw and auxiliary materials used, the added amounts, the addition order, and the fermentation conditions at each stage are the same as those in Example 1, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 1 is changed to add Lactobacillus plantarum ATCC14917.

[0059] Comparative Example 2

[0060] The types of raw and auxiliary materials used, the added amounts, the addition order, and the fermentation conditions at each stage are the same as those in Example 1, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 1 is changed to add Lactobacillus plantarum ACCC11095.

[0061] Comparative Example 3

[0062] The types of raw and auxiliary materials used, the added amounts, the addition order, and the fermentation conditions at each stage are the same as those in Example 1, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 1 is changed to ferment with Lactobacillus plantarum ATCC8014.

[0063] Comparative Example 4

[0064] The types of raw and auxiliary materials used, the added amounts, the addition order, and the fermentation conditions at each stage are the same as those in Example 2, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 2 is changed to add Lactobacillus plantarum ATCC14917.

[0065] Comparative Example 5

[0066] The types of raw and auxiliary materials used, the added amounts, the addition order, and the fermentation conditions at each stage are the same as those in Example 2, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 2 is changed to add Lactobacillus plantarum ACCC11095.

[0067] Comparative Example 6

[0068] The types of raw and auxiliary materials used, the added amounts, the addition order, and the fermentation conditions at each stage are the same as those in Example 2, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 2 is changed to ferment with Lactobacillus plantarum ATCC8014.

[0069] Comparative Example 7

[0070] The types of raw and auxiliary materials used, the added amounts, the addition order, and the fermentation conditions at each stage are the same as those in Example 3, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 3 is changed to add Lactobacillus plantarum ATCC14917.

[0071] Comparative Example 8

[0072] It is the same as the types of raw and auxiliary materials, addition amounts, addition sequences, and fermentation conditions at each stage used in Example 3, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 3 is changed to add Lactobacillus plantarum ACCC11095.

[0073] Comparative Example 9

[0074] It is the same as the types of raw and auxiliary materials, addition amounts, addition sequences, and fermentation conditions at each stage used in Example 3, except that Lactobacillus plantarum LP-GB 01-21 in the fermentation stage of step (3) in Example 3 is changed to add Lactobacillus plantarum ATCC8014 for fermentation.

[0075] Table 1 Analysis Table of Fermented Juice Quality

[0076]

[0077] According to the provided data, it can be observed that the juice prepared by the method of the present invention exceeds the comparative method in terms of the contents of γ-aminobutyric acid, lactic acid, total polyphenols, total flavonoids and antioxidant activity. This indicates that the fermented juice prepared with Lactobacillus plantarum LP-GB 01-21 is not only rich in nutrition but also has a significant antioxidant effect.

[0078] Sensory evaluation was carried out on the fermented juice. The results showed that the fermented juice prepared with Lactobacillus plantarum LP-GB 01-21 greatly enhanced the floral and fruity aromas of the juice and reduced the pungent taste; in terms of taste, Lactobacillus plantarum LP-GB 01-21 can improve the sweetness and umami taste of the fermented juice, reduce the bitterness, making the taste and flavor of the fermented juice softer, richer and more acceptable to the public.

[0079] Table 2 Analysis Table of Sensory Evaluation (Flavor) Results of Fermented Juice

[0080]

[0081] Table 3 Analysis Table of Sensory Evaluation (Taste) Results of Fermented Juice

[0082]

[0083]

[0084] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the claims.

Claims

1. A method for preparing a fermented fruit juice rich in GABA, lactic acid, polyphenols and flavonoids, characterized in that, The method comprises the following steps: (1) Raw material treatment: Dilute the original fruit juice pulp to a sugar degree of 12 - 14 °Brix to obtain a fruit juice raw material; (2) Strain activation: Activate Lactobacillus plantarum LP - GB 01 - 21 to obtain a seed solution; (3) Fermentation: Inoculate the seed solution obtained in step (2) into the fruit juice raw material obtained in step (1), and ferment at 35°C - 37°C for 8 - 12 h to obtain a fermentation broth; (4) Filter and sterilize the fermentation broth obtained in step (3) to obtain the fermented fruit juice; The preservation number of Lactobacillus plantarum LP - GB 01 - 21 is CCTCC M 209102.

2. The method according to claim 1, wherein The biomass of the seed liquid described in step (3) is 1×10 6 CFU / mL; in the fruit juice raw material, the inoculation amount of the seed liquid is 1%-5% v / v.

3. The method according to claim 1, wherein The end point of the fermentation in step (3) is that the biomass of Lactobacillus plantarum is 8.50 lg CFU / mL - 9.5 lg CFU / mL or more, and / or the total acid calculated as lactic acid reaches 2.03 g / 100 mL or more.

4. The method according to claim 1, wherein The fermentation in step (3) is static fermentation.

5. The method according to claim 1, wherein The original fruit juice pulp in step (1) includes wolfberry original pulp, apple concentrated juice or mulberry concentrated juice.

6. The method according to claim 1, characterized in that, The preparation method of the seed solution in step (2) is: Culture Lactobacillus plantarum LP - GB 01 - 21 in MRS medium at 35°C - 37°C for at least 18 h.

7. The fermented fruit juice prepared by the method according to any one of claims 1 - 6.

8. The application of Lactobacillus plantarum LP - GB 01 - 21 in the preparation of a fermented fruit juice rich in GABA, lactic acid, polyphenols and flavonoids.

9. The application of Lactobacillus plantarum LP - GB 01 - 21 in improving the antioxidant property of fruit juice.

10. The application of Lactobacillus plantarum LP - GB 01 - 21 in the preparation of fermented foods.

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